Why Are My Sponge Cakes Not Rising in the Fan Oven? Common Causes and Solutions

If your sponge cakes aren’t rising in a fan oven, chances are the heat’s just too strong or uneven. The eggs end up setting before the cake gets a real shot at rising.

Fan ovens move hot air fast, which can dry out the batter and shut down the rising process way too soon. That stops those gas bubbles from expanding enough to lift your sponge.

Sometimes, you might lose the air you worked into the eggs by folding in the flour too roughly. Not beating the mixture enough at the start can also hurt the rise.

Using old or too little raising agent makes things worse, especially with the way fan ovens dry everything out.

If you want to dig deeper into why sponges don’t rise, check out this discussion on sponge cakes not rising and look into oven temperature tips.

Common Reasons Sponge Cakes Fail to Rise in a Fan Oven

When your sponge cake stays flat, there are a bunch of possible culprits. Temperature, ingredient measurements, how you mix, and even when you open the oven door can all play a part.

Incorrect Oven Temperature

Fan ovens cook faster since the fan keeps the hot air moving. Sometimes that means your cake rises unevenly or collapses if things get too hot.

If the oven’s cranked up too high, the edges set before the center rises. You might end up with a domed cake that cracks or deflates.

Try lowering the fan oven temperature by about 20°C (or 35-40°F) from what your recipe says. So, if it calls for 180°C, go with 160°C instead.

Grab an oven thermometer to double-check what your oven’s actually doing. Those dials can be pretty unreliable.

Inaccurate Ingredient Measurements

Measuring ingredients right is more important than most people think. Flour and raising agents like baking powder need to be spot on.

Add too much flour and your batter gets dense, so it won’t rise. Not enough, and the cake could collapse after rising.

If you go heavy on baking powder or baking soda, the cake rises too fast and then falls.

A kitchen scale beats measuring cups for accuracy. Don’t scoop flour straight from the bag—fluff it up first and spoon it in, or you’ll have way too much.

Over-Mixing or Under-Mixing the Batter

Mixing’s a balancing act. You need to trap air, but not overdo it.

If you mix too much, you knock out those precious air bubbles and the batter flattens. Plus, you’ll get a tough texture.

Under-mixing leaves lumps and doesn’t get enough air in, so the cake won’t rise well.

When you fold in the flour, do it gently and stop as soon as the flour’s gone. That keeps things light and airy.

Premature Opening of the Oven Door

Opening the oven door too soon lets out the heat and drops the temperature fast.

That sudden change can make your sponge cake sink.

Try not to open the oven for at least the first 20 minutes. That’s when the cake needs steady heat to rise and set.

If you can’t resist checking, use the oven light or make it quick. Keep that door shut as much as possible.

You can pick up more tips at the Reddit Baking Forum and BBC Good Food’s cake problems fixed.

Expert Tips for Achieving a Well-Risen Sponge Cake

To help your sponge cake rise in a fan oven, you need to manage temperature, heat flow, and even your choice of baking tin. Sometimes, just moving your cake to a different shelf or letting your oven preheat longer can change everything.

Optimal Shelf Placement in a Fan Oven

Stick your cake on the middle shelf. The fan pushes hot air everywhere, but if you put the cake too close to the top or bottom, it won’t cook evenly.

Edges can cook way faster than the center, which ruins the rise. Keep the cake away from oven walls, too.

Give your baking tin some space so air can circulate. That way, the whole cake cooks at the same speed and rises evenly.

Proper Preheating Techniques

Always preheat your fan oven to the right temperature before you start baking. A steady temperature from the start helps your cake rise the way it should.

If the oven’s too hot, the outside sets too fast and the inside can’t expand. Set the fan oven a bit lower than a regular oven—so if a recipe says 180°C, go for 160–170°C.

Use an oven thermometer to double-check, since fan ovens aren’t always consistent.

Choosing the Right Baking Tin Size

Picking the right baking tin size really matters. If your tin’s too small, the batter piles up and takes longer to bake.

That can leave you with a dense, heavy cake. On the flip side, a tin that’s too big spreads the batter thin, so the cake doesn’t rise much.

I usually stick with whatever size the recipe suggests. For most sponge cakes, that’s a round 8 or 9-inch (20–23 cm) tin.

Switching tin sizes? You’ll need to tweak the baking time and temperature. A deeper batter means you should lower the heat and bake it longer, but a shallow one cooks faster.